Flowmeter



ERl

FHM

am 3. 4 9 1 3.. uw u A Inventor' Patented Aug. 3, 194:3

UNITED4 STATES PATENT OFFICE FLOWMETER.

Emory Frank Stover, Wynnewood, Pa.

Application November 1, 1941, Serial. No. 417,487

13 claims. (ci. 'z3- 205) My invention relates to improvements in fluid meters and particularly to meters used in connection with Venturi tubes, orifices. flow nozzles, Pitot tubes, and other primary metering devices. in which .the rate of flow through a conduit is proportional to the square root of the differential pressure applied to a pressure responsive device by one of the primary devices, and the meter is adapted for obtaining the rate of ow through the conduit and indicating the rate of ow on a scale of uniform divisions.

The object of my invention is to provide a flofw meter embodying a novel lever system, having first and second armsloaded with concentrated and uniform loadings, respectively, and adapted for producing a reading directly proportional to the rate of ow. y

A further object is to arrange the lever arms so that the first one of the arms may be loaded with a loading having a xed lever arm about a pivot axis, thus forming a concentrated load which is adapted to be varied as the differential pressure, which latter is proportional to the square of the rate of flow, and provide means for loading the second arm as a cantilever beam, with a uniform load applied at the pivot axis of the second arm and extended toward the free end of the latter until the moment of theuniform load about said axis balances the moment of the concentrated load upon the first arm. When the arms are in balance the moment of the uniform load upon the second arm is proportional to the square of the length of the uniform load` upon the second arm, and the length of the uniform load` represents the square root of the differential pressure, and therefore said length is a lineal measurement of the rate of flow through the conduit.

A further object is to provide means for indicating the length of the uniform load which is a direct measurement of the .rate of fluid flow through the conduit.

A further object is to provide a lever system adapted for having a uniform load applied to the second lever arm, which load may be in the form of a liquid such as mercury, or a continuous Vseries of weights, such as a chain.

further object is to arrange actuating means for moving the uniform load upon the second arm to establish equilibrium of the lever system, which actuating means is adapted to be operated by either pneumatic power, or electrical power. and controlled by the unbalancingl of the lever system. A further object is `to provide a construction of the lever system employing lever 'arms mounted upon separate axes and connected by a link which is adjustable relatively tovsaid axes, and adapted for making various adjustments enabling the meter to be used without other alterations for a wide variety of maximum differential pressures.

These together with various other novel features of construction and arrangements of the parts, which will be hereinafter more fully described and claimed, constitute my invention.

, Referring to the accompanying drawings:

Fig. l is a vertical section as on line I-I Fig. 2, showing a preferred form of my invention.

Fig. 2 is a transverse vertical section on line 2 2 Fig. 1.

Fig. 3 is a vertical sectional view of a modified form of my invention adapted for employing weights for applying4 a uniform load upon the second lever arm.

Fig. 4 is a vertical sectional View of al lever system having lever' arms mounted upon separate axes and connected by a compensating link which is adjustably mounted upon said arms, and showing pneumatic means for moving the uniform load upon the second arm.

Fig. 5 is a transverse vertical section on line 5-5 Fig. 4.

Fig. 6 is a vertical section on line 6 6 Fig. 5.

In the drawings', in which like reference characters refer to like parts, 5 represents my novelA meterfshown connected witha conduitI 6 through which fluid is adapted to flow in the direction of the arrow. VA primary metering device in thev `forming-'one leg of `the U.tube, or manometer 8.

The tubes I3 and I4.of the manometer contain mercury I5, which is `subjeclsedto the differential pressure for moving the mercury for purposes hereinafter described.

The meter, as shown in Figs. 1 and 2, embodies a lever system I6, which includes a first lever arm I'I having an enlarged head,` or block I8,

`secured to a bridge plate I9, having knife edges 20, forming a Divot axis 2|. The knife edges 90 are pivotally supported upon fixed bearings 22 and 23, formed upon a bracket 24, having a base plate adapted to be mounted upon a fixed support.

The lever arm I1 is provided with a receptacle 28 adapted for receiving a load having a constant moment arm about the axis 2l. Said load, in the form shown in Fig. 1, consists of mercury I5a, adapted to be forced into the receptacle 28-through a exible pipe 29, connected with the header I 9, and communicating with the leg I4 of the U-tube ormanometer 8. The receptacle 26 is also connected by a flexible pipe 3G with the header I0 and is in communication, through a pipe 3l, with the low pressure side oi the Venturi tube 1. When there is flow of fluid through the conduit 6 a diiierential pressure is created with forces the mercury from the manometer 6 into the receptacle 28 and unbalances the lever system.

A second lever arm is included 1n the lever system, which arm is in the form of a tube adapted for containing mercury 36, for loadmg the arm 35 as a cantilever beam with a uniform loading.

The arm 35 is mounted for pivotal movement about the same axis 2l as the first arm i1, and said arm 35 is movable with the arm I1 about said axis ZI. The arm 35 is secured at its end adjacent to the axis 2|, in a head or block 31, which latter is secured for axial adjustment, relatively to the block I8, and also to the bridge a bracket secured to the bridge plate I9. The

bracket 40 has a stud shaft 4I which occupies an axial recess formed in the block 31. A spring 42 encircles the shaft 4I andtends to press the end faces of the blocks I8 and 31 together, thereby holding an annular projection 43, formed upon one of the blocks in an annular recess formed 1n the opposite block, as shown in dotted lines in Fi 2.

he blocks I8 and 3.1 are secured vin alignment upon the axis 2I by radially projecting face plates 4-5 and 46, which are secured upon the respective'blocks and are adapted to be secured together by a bolt 41 for rigidly locking the arm 35 in an adjusted position relatively to the arm I1. By this means the radial position of the arm 35, about the axis 2|, may be adjusted to compensate for variations in the size of the -bore of the tubular arm 35, which latter is preferably formed of glass. Said means also permits the adjustment of the meter for difierent maximum values of diierential pressure without changing the length of a scale provided for measuring the length of the uniform load upon the arm 35. Said adjusting means also permits the arm 35 to be readily detached from the arm I1.

The bridge plate I9 is retained upon the bearings 22 and 23 by retaining plates 48 and 49, detachably secured to said bearings. By removing the plates 48 and 49 the arms I1 and 35i may be readily removed from the bearings 22 and 23.

The lever arm 35 is adapted to be supplied passage 56 which communicates with an axial passage 51, formed in the block 31, of the arm 35. Said passage 51 communicates with a chamber 58, formed in the block 31 and located at the open end of the tubular arm 35. This construction forms a-means for applying a uniform load upon the arm 35, with `the load having a length extending from the pivot axis 2l toward the free end of said arm.

The lever arm 35 is inclined from a horizontal position, as shown in Fig. 1, so that the liquid 36 will iiow from the arm 35 and reduce, or entirely remove, the load from the arm 35, when the cylinder 5u is extended relatively to the y plunger 5l.

The cylinder 56 has secured thereon a rack 66, which is engaged by suitable gearing 6I,

adapted to be rotated in opposite directions by A scale 16, having uniform graduations thereon, is secured upon the xed head 52 of the Y plunger 5l, and a pointer 1l is secured upon the movable cylinder '56. The graduations upon the scale 111 correspond to the rate of uid flow through the conduit 6, and the position of the pointer relatively to the scale will directly indicate the rate of fluid ow through the conduit.

Upon the free end of the arm 35 is an air container 13 adapted for sealing the arm 35 for preventing air from coming into contact with the mercury and oxidizing the same. Said container has suiiicient capacity to allow the air to expand and contract. The container 13 also provides means for preventing the loss of mercury in the event the meter is inverted.

A manually adjustable weight 15 is in threaded engagement with a rod 16 secured to the block I8. The weight 15 provides means for balancing `the lever system when the arms I1 and 35 are with the mercury 36 from the cylinder 5D, which not loaded.

The operation of the meter shown in Fig. 1 is as follows: When there is fluid flowing through the conduit 6 a differential pressure will be produced which is proportional to the square of the rate of flow, and said pressure will force the mercury I5 from the pressure responsive deviceI into the receptacle 28 and form a concentrated load I5a upon the rst arm I1. The lever system is thus thrown out of balance, causing a movement of the lever arms which will close the circuit between the switch plates '66 and 68 and start the motor in a direction for moving the cylinder 56 and the piston 5I, relatively to each other, thereby forcing the mercury 36 into the tubular arm 35 and forming a uniform load 36a upon the second lever arm 35, which latter load will have a moment suicient to balance the moment of the load I5ar upon the rst lever arm I1. When the lever system is restored to a balanced position the motor will be stopped by the opening of the circuit between the switch plates 66 and 68.

A reduction in the rate of iiow will reduce the differential pressure and allow the mercury I5a to ow from the receptacle 28 to the responsive device 8 and reduce the load I5a on the arm I1, causing the latter to move and engage the switch plates 66 and 61 for rotating the motor in the reverse direction for extending the cylinder 56 relatively to the plunger 5I, thereby allowing the the rod 92 to thel rst lever arm 8|, which load mercury 36a to now from the arm 85 until the system is again balanced and the motor stopped by the opening of said switch plates; thus the lever system will tend to maintain the lever` arms in balance at any rate of ow through the conduit. The relative positions of the scale 10 and the pointer 1| will indicate the rate of flow of fluid through the conduit 6.

Fig. 3 illustrates a form of my invention which employs means for loading the second arm of the lever system with weights in the form of a chain adapted to form a uniform load.

A beam 80, forming lever arms 8| and l82, is provided with transversely projecting stud shafts 83, shown in dotted lines, said shafts 83 have knife edges which are mounted upon bearings 84 and form a pivot axis 85 for the beam 80.

The arm 8| is adapted vto receive a concentrated load which varies as the square of the rate of flow of fluid through a conduit. The second arm 82 of the beam is constructed with a track 81 adapted for guiding a chain 88 throughout the length of the arm 82 to form auniform load having a length extending from the pivot axis 85 toward the free end of the arm 82.

The beam 80 is provided with an aperture 90 located adjacent to the pivot axis 85, through which aperture the chain 88 may be moved from a suspended position directly in vertical alignment with said axis 85, to a horizontal position upon the track 81 of the arm 82, for maintaining the beam in balance against the concentrated load applied, through a rod 92 to the first arm 8|, at the fixed point of attachment 93.

The chain 88 is movable relatively to the length of the arm 82 by means of a sprocket wheel 95,

A secured upon a shaft 96, mounted for rotation upon a bearing 91 which is 'secured to the beam 80. A reversing motor 98 is mounted upon the bearing 91, with the motor shaft 99 positioned vertically;` a worm is secured upon the shaft 99 and meshes with a worm wheel |0|, secured upon said shaft 96, and adapted for rotating the sprocket wheel 95Y having radially projecting pins adapted for engaging the chain 88.

The motor 98 is included in an'electric circuit |02, which is controlled by a. switch |03, having a movable contact plate |04, mounted on one end of the beam 80, and fixed contact plates |05 and |08, mounted upon the base of the switch |03.

The means for applying a concentrated load to the arm 8 |V vmay be in the form of a manometer 8,

as shown'in Fig. 1, or it may be in the form of a wel1 known pressure responsive deviceV |08. Said device |08 includes a plunger |09, moyably mounted within acasing |10, forming a low pressure chamber ||2 and a high pressure chamber ||3. Said chambers are separated by a lflexible diaphragm ||4, having the plunger |09 secured thereto. The rod 92 is attached to the plunger |09.

y A primary differential pressure producing device ||5 has a pipe H6 which connects the high pressure side of said device ||5 with the high pressure chamber ||3 of the responsive device |08, and a pipe ||1 which connects the low pressure side of said device ||5 with the low pressure chamber ||2 of the device |08, which latter is adapted for applying a concentrated load through varies as the square of the rate of flow of fluid through the conduit H9. l

When there is flow through the conduit ||9 a force will .be applied through the rod 92 to the lever arm8| which will move the beam 80 out 'of balance and engage the switch plates |04 and |05, and operate the motorf98 for rotating the sprocket wheel 95. The wheel 95 is thus rotated in a direction for extending the chain 88 upon the second lever arm 82 until a uniform load 88a is applied to the arm 82 whicnwill restore the 82, to exceed the concentrated load upon the first -ing |24, also secured upon the beam 80.

arm 8|, the beam 80 will move and engage the switch plates |04 and |08 and Ioperate the motor for reducing the length of the uniform load relatively to the arm 82 and restore the beam to its balanced position. By this arrangement the chain 88 will be adjusted to a length upon the arm 82 which will form a uniform load 88a, having a moment which will maintain the beam in balance against a concentrated load applied to the first arm 8| by the rod 92. When the beam is so balanced the length of the uniform load on the second arm 82 will be directly proportional to the rate of flow of fluid through the conduit H9.

A scale |20 is mounted upon the beam 80 and a pointer |2| is mounted upon a gear wheel |23, which latter is mounted for rotation upon a bear- The gear wheel |23 is rotated at a reduced speed by means of a smaller gear wheel |25, secured upon the shaft 96, as shown in dotted lines Fig. 3. The scale |20 is graduated proportionally to the rate of flow, and the .position of the pointer |'2|, relatively to thescale, will showa reading which is a measurement of the rate of fluid flow through the conduit ||9.

The pointer |2| is arranged to engage the beam 80, which latter forms a stop for the pointer adjacent to the zero position upon the scale when there is no fio'w through the conduit, thereby insuring the stopping of the sprocket wheel 95 in a position forvsupporting the chain in a vertical position adjacent to the pivot axis 85, with the sprocket wheel 95 in engagement with the end of the chain, and forming a support for the latter.

The operation of the meter shown in Fig. 3 is similar to the operation of the meter shown in Fig. 1, except that the chain 88 is employed as the means for applying the uniform load to the second lever arm 82.

When there is uid owing through the conduit H9 the chain 88 will be extended upon the arm 82 for loading the latter as a cantilever arm, with a uniform load forming a moment about the axis which is proportional to the square of the length of the uniform load and equal to the moment of the concentrated load applied to the first arm 8| by the responsive devicel |08, and the pointer |2| will give a reading upon the scale which will indicate the rate of -fiow of fluid through the conduit I I9.

lThe meter illustrated in Fig. 4 embodies a 1ever system having lever arms mounted for pivotal movement upon separate supports, or axes, and includes means adapted for adjustably coupling the arms for varying the ratio of the arms. l

The lever system shown in Fig. 4 includes a beam |30 having stud shafts |3| provided with knife edges pivoted upon a fixed support |32 and forming a pivot axis |33 for the beam |30. The arm |35 of the beam |30 forms the first arm of the lever system and is adapted to be loaded with a concentrated load applied by a rod |36.

A conduit |38 is connected with a primary device |39, which produces a diierential pressure which acts upon a pressure responsive device |40,

which in turn acts upon the rod |36 pivotally conl nected with the first arm |35. A force applied is as follows: When the lever system is in avates the free end of the second arm |55, thereby through the rod |36 loads the rst arm |35 with a concentrated load forming a moment which varies as the square of the rate of flow of fluid through the conduit |38.

A member, or arm |42, of the beam |30, is provided with a sleeve |43 which is slidably mounted upon the member |42. The sleeve |43 has stud shafts |44 provided with knife edges which form means for pivotally connecting a link |45. Said link has its opposite end pivotally connected with stud shafts |46 provided with knife edges and secured upon a sleeve |41, similar to the sleeve |43. Said sleeve |41 is slidably mounted upon a member, or arm |48, pivotally mounted upon a support |49. Said arm |48 is secured upon a head or block |50, which in turn is secured upon a bridge plate |52, having knife which are mounted upon the supports |49 which from a pivot axis |53.

An arm |55 forms the second arm of the lever system. Said arm |55 is arranged in an inclined position with its lower end secured in said block |50. a uniform load having a length from said axis |53 which will form a moment proportional to the square cf the length of the uniform load. Said uniform load upon the arm |55 tends to balance the lever system against the moment of the first arm |35, which is proportional to the square of the rate of flow through the conduit, and the length of the uniform load upon the second arm |55 is a direct measurement of the rate of ow through the conduitl |38.

By adjusting the sleeves |43 and |41 upon the members,'or arms |42 and |46, the ratio of the lever arms |35 and |55 may be varied to obtain equilibrium of moment arms of said loads, with different maximum values of the load applied to the first arm |35.

The second arm |55 is in the form of a tube adapted to be loaded with a uniform load in the form of mercury |56 from a manometer, or container |58, which is connected by means of a flexible pipe |59 with said head or block |50, having a passage in communication with the bore of the second arm |55 at a point adjacent to the axis |53.

The manometer, or container |58, for the mercury |56, is in the form of a U-tube having said pipe |59 forming one leg thereof, and a glass tube |60 forming the opposite leg. The leg |60 is connected with a pipe |62 adapted for supplying air underpressure for forcing the mercury through the pipe |59 into the bore of the arm |55. The air is supplied from a tank |63 through a pipe |64 to a valve |65. Said valve |65, as shown in Figs. and 6, comprises a casing |66 mounted in a Xed position upon a support |61, and a shaft |68 mounted for rotation upon the axis of the casing. The shaft |58 isl secured upon the bridge plate |52 and is rotatable by the movements of the second arm |55. Said shaft |68 is provided with a chamber |69, adapted for controlling communication from the air supply pipe |64 to the pipe |62, and also from the pipe |62 to the atmosphere through an exhaust aperture formed in the casing |66.

The operation of the meter shown in Fig. 4

Said arm |55 is constructed for receiving rotating the shaft, or valve stem |68, for admitting air under pressure fromthe pipe |64 to the pipe |62, which forces the mercury from the leg |60 through the pipe |59 to the bore of the arm |55, and restores the lever system to equilibrium.

When the flow through the conduit decreases, the concentrated load acting upon the rst arm |35 will be reduced, and the free end of the arm |55 will move downwardly and operate the valve stem |66 to close the air supply pipe |64 and open communication between the pipe |62 and the aperture |10, leading to the atmosphere, thereby reducing the air pressure upon the mercury in the tube |60, and allowing the mercury to ow from the arm 55, into the tube |60, and again restoring the lever system to equilibrium, thus establishing a length of the uniform load upon the arm |55 which Will be a direct measurement of the rate of flow through the conduit. A scale |15 is mounted adjacent to the leg 60, of the U-tube, and is adapted for indicating the rate of flow of uid through the conduit.

By adjusting the link |45 to various positions relatively to the pivot axes |33 and |53, of the lever system, the meter may be adjusted for different maximum differential pressures, for obtaining equilibrium of moment of the loads upon the arms |35 and |55, with different maximum Values of the concentrated load upon the arm |35.

The means for operating the meter by air under pressure, as above described, is of great advantage where electricity cannot be employed in certain buildings due to fire hazards.

The principle upon which my novel meter operatesis as follows: The concentrated load upon the rst lever arm has a magnitude proportional to the differential pressure and proportional to the square of the rate of flow through the conduit. The concentrated load acts at a fixed distance from the pivot axis of the first arm and produces a. moment proportional to the square of the rate of fioW.

The uniform load upon the second lever arm is extended until-it balances the concentrated load upon the first arm. The moment of said uniform load is proportional to the square of the length of said uniform load.

When the moment ofthe second arm is balanced by a moment of the rst arm, which latter is proportional to the square of the rate of ow, the result obtained is that the first power of the length of the uniform load is a measure of the rst power of the rate of iiow, and the scale indicating the length of the uniform load will give a measurement of the rate of flow through th conduit.

Various changes in the construction and arrangement of the parts may be made without departing from any invention.

I claim:

1. A meter for measuring the lcw of uid in a conduit comprising a bal/anced lever having cantilever arms, means for loading a rst arm of said lever with a concentrated load having a constant moment arm, a primary metering device for producing a differential pressure proportional to the square of the rate of flow through the conduit, a

will be directly proportional to the rate of now. i

pressure responsive device responsive to said differential pressure cooperating with said first mentioned means and arranged for varying said concentrated load to the response of said dinerential pressure, means for loading a second arm of said lever with a uniform load having a length measured from the origin of the second arm` which will form a moment proportional to the square of the length of said uniform load, a head securing said arms together at their origin, a support forming a pivot axis for said head with said arms extending in different directionsrfromsaid axis, said head having an axial passage extending transversely to the length of said second arm through which passage said uniform load is adapted to be moved to and from said second arm directly at said pivot axis, and means actuated by the unbalancng of said arms for varying said uniform load upon the second arm for maintaining equilibrium of moments of the loads upon said arms and establishing a length of said uniu form load which is a measurement of the rate of flow.

2. A meter for measuring the flow of fluid in ai conduit comprising a lever having cantilever arms, a support forming a pivot axis for said lever, means for loading one of said arms with a 5. A meter for measuring the now of fluid in a conduit comprising balanced cantilever arms, means for loading a rst one of said arms with a concentrated load having a moment proportional to the square of therate of now, means upon a second one of said arms forming a guide extending parallel with the length of the second arm, said guide extending from the origin of said second arm toward the free end of the latter. said second arm having a passage located adjacent to the origin thereof and forming a communication with said guide, said passage extending transversely to the length of said second arm, and

means for applying a load through said passage .a conduit comprising balanced cantilever arms,

concentrated load having a moment about said axis proportional to the square of the rate of flow, means for loading a second arm with a uniform load forming a moment about said axis proportional to the square of the length of said uniform load, means for varying the length of said load upon the second arm for balancing said moments and establishing a length of said uniform load whic-h is proportional to the rate of flow, and means for adjustably securing said arms together adjacent to said axis adapted for adjusting the radial positions of said arms relatively to each other for varying the ratio of said arms.

3. A meter for measuring the flow. of fluid in a conduit comprising a lever having cantilever arms, a support forming a pivot axis for said lever, means for loading one of said arms with a concentrated load having a moment about said axis proportional to the square of the rate of now, means for loading the second one of said arms witha uniform,v load, means Vfor varying the length of said uniform load upon the second arm for balancing said lever, heads upon which the adjacent ends of the respective arms are secured,

` a bridge plate having a knife edge mounted upon said support, means securing one of saidi heads to said plate, means mounting said heads together for rotation about said axis, and locking means upon said heads adapted for securing the heads together with the arms in adjusted radial posi-V tions relatively to each other for varying the ratio of said arms. l

4. A meter for measuring the flow of fluid in a conduit comprising balanced cantileve arms, means for loading a first one of said arms with vab. concentrated load having a moment proporthrough said passage for forming a moment of the cylinder relatively to the plunger for moving the second arm which will balance the moment of the first `arm and the length of said uniform load means for loading a iirst one of said arms with a concentrated load having a moment proportional to the square of the rate of flow, a second one of said arms having an axial bore extending throughout its length, means mounting said second arm inn a position inclined upwardly` from its origin, a container adapted for containing liquid, means mounting the container independently of said arms, a flexible connection forming a communication between the container and said bore, means adapted for forcing the liquid from the container into said bore for loading the second arm with a uniform load forming a moment about the origin of the second arm proportional to the square of the length of said uniform load, and control means actuated by the unbalancng of saidarms adapted for actuating said means for forcing the liquid into said bore for varying the amount of liquid within said bore for maintaining equilibrium of the moments of the loads upon said arms and establishing a length of said uniform load which is a measurement of the rate of W. f I

7. A meter for measuring the lowof fluid in a conduit comprising a lever having lever arms, means forming a pivot axis about which the lever is adapted to be balanced, means for loading a first one of said arms of said lever with a concentrated load having a moment about said axis t proportional to the square of the'rate of flow, a

' means mountingl said second arm in a position inclined upwardly from its origin, a plunger mounted in a. fixed position, a cylinder mounted for movement upon the plunger, a liquid contained Within the cylinder, a. flexible pipe arranged for conducting the liquidlto and from said bore, actuating means arranged for moving the liquid into said bore for loading the second arm with a uniform load forming a moment about said axis proportional to the square of the length of the uniform load, control means actuated by the unbalancng of said arms adapted for controlling said actuating means for varying the amount of liquid in said bore for maintaining equilibrium of said arms, a scale graduated proportionally to the rate of flow,a pointer, and means mounting the pointer and scale for relative movements corresponding to the relative movements of the 8. A meter for measuring the ow of fluid in a conduit comprising a lever having arms, means forming a pivot axis about which said lever is adapted to be balanced, means for loading a first arm of said lever with a concentrated load having a moment about said axis proportional to the square of thel rate of flow, a second arm of said lever having an axial bore, means mounting said second arm in a position inclined upwardly from its origin, a cylinder, mercury contained Withinthe cylinder, a plunger, means mounting the plunger in a xed position, a flexible pipe connection between the cylinder and said bore, an electric circuit, a reversing motor included in said circuit and arranged for moving the cylinder relatively to the plunger for transferring the mercury to and from said bore for loading the second arm with a uniform load forming a moment about said axis proportional to the square of the length of said uniform load, and a switch included in said circuit and actuated by the unbalancing of said arms for operating the motor in a direction for maintaining equilibrium of the moments of the loads upon said arms and establishing a length of said uniform load which is a measurement of the rate of iiow.

9. A meter for measuring the ow of fluid in a conduit comprising a balanced lever system having cantilever arms, means for loading a first arm of said system with a concentrated load having a moment about the origin of the first arm to the free end of the latter, a stationary container adapted for containing a liquid, a iiexible connection forming a communication between the container and the end of said bore located adjacent tothe origin of said second arm, a source of air pressure supply, a connection between said source and said container adapted for forcing the liquid from the container into said bore for loading the second arm with a uniform load forming a moment proportional to the square of the length of said uniformload, means mounting the second arm in an inclined position whereby the liquid will tend to fiow toward the container when the air pressure is reduced, and control means actuated by the unbalancing of the system adapted for controlling vthe air under pressure acting upon the liquid in the container for varying the amount of liquid within said bore for maintaining equilibrium of the moments of the loads upon said arms 'and establishing a length of said uniform load which is a measurement of the rate of flow.

10. ,A meter for measuring .the flow of fluid in a conduit rcomprising a balanced lever having cantilever arms, means for loading a first arm of said lever with a concentrated load having a moment about the origin of the first arm proportional to the square of vthe rate of flow, a second arm of said lever forming a guide extending parallel with the length thereof, weights mounted for movement upon said guide and adapted to form a uniformA load having a length measured from the origin of the second arm which will form a moment proportional to the square of the length of the uniform load and balance the mol ment of the first arm, and means actuated by the unbalancing ofsaid arms and adapted for movmaintaining equilibrium of moments of the loads upon said arms and establishing a length of said uniform load which is a measurement of the rate of flow.

11. A meter for measuring the flow of fluid in a conduit comprising a lever 'having lever arms, means forming a pivot axis about which the lever is adapted to be balanced, means for loading a first arm of said lever with a concentrated load having a moment about said axis proportional to the square of flow, means upon a second arm of said lever forming a guide extending parallel with the length thereof, a series of weights connected in chain formation, mechanism located adjacent to said axis adapted for normally supporting said weights free of said guide, means for operating said mechanism for extending said weights upon vthe guide to form a uniform load having a length measured from said axis which will form a moment of the second arm proportional to the square of the length of the uniform load and balance the moment of the first arm, and control means actuated by the unbalancing of said lever and adapted for controlling said means for operating'said mechanism for varying the length of the uniform load upon said guide for maintaining equilibrium of the moments of the loads upon said arms and establishing a length o'f said uniform load which is a measurement of the rate of flow.

12. A meter of the character described comprising a balanced system of levers having cantilever arms, meansmfor applying a concentrated load at a fixed point upon one of the arms of said system forming a montent proportional to aforce to be measured, means for applying a uniform load to a second arm of said system, means for varying the length of said uniform load from the origin of the second arm to a length upon the latter arm which is proportional to the square root of said concentrated load when said system is in balance, said system having a link associated with said arms and arranged for opposing the action of said loads upon the respective arms, means mounting said link for adjustment relatively to the origins of said arms for varying the ratio of the action of said loads for obtaining equilibrium of moments for different maximum values of said concentrated load, and means for measuring the length of said uniform load.

13. A meter for measuring the flow of uid in a conduit comprising a system of levers having lever arms, supports forming separate pivot axes for said levers, means for loading one arm of a lever of the system with a concentrated load having a moment proportional to the square of the rate of iiow, means for loading one arm of another of the levers of said system as a cantilever arm with a uniform load, said levers including member arms respectively, said system including a link connecting said member arms, means slidably mounting the link upon said mem'- ber arms for adjustably coupling said levers for varying the ratio of the member arms for obtaining equilibrium of moments with different maximum values of said concentrated load, means for varying the length of said uniform load upon vthe cantilever arm for balancing said moments and establishing a length of said uniform load which is proportional to the rate of ow, and means for measuring the length of said uniform load. EMORY FRANK STOVER. 

